From: Yinghai on
On 05/19/2010 05:01 PM, Mathieu Rondonneau wrote:
> it' s not in ISA space.
> once loading the NVIDIA driver, the warnign oops shows up.
> 4K starting at 0x9f800 (i.e. to 0xa007ff) overlap with the ISA space
> (starting at 0xa0000).
>
> When I don' t load the driver, no oops.
> So I am assuming nvidia driver request 4K of memory, that happens to
> be available in the bios area.
>
> I think that there is a check missing somewhere to report that
> available RAM buffer is already reserved (by BIOS) so we need to get
> it from somewhere else.

please check if this patch fix the problem.

Subject: [PATCH] x86: Align e820 ram range to page

To workaround wrong BIOS memory map.

Signed-off-by: Yinghai Lu <yinghai(a)kernel.org>

---
arch/x86/kernel/e820.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -910,6 +910,47 @@ static int __init parse_memmap_opt(char
}
early_param("memmap", parse_memmap_opt);

+static void __init e820_align_ram_page(void)
+{
+ int i;
+ bool changed = false;;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *entry = &e820.map[i];
+ u64 start, end;
+ u64 start_aligned, end_aligned;
+
+ if (entry->type != E820_RAM)
+ continue;
+
+ start = entry->addr;
+ end = start + entry->size;
+
+ start_aligned = round_up(start, PAGE_SIZE);
+ end_aligned = round_down(end, PAGE_SIZE);
+
+ if (end_aligned <= start_aligned) {
+ e820_update_range(start, end - start, E820_RAM, E820_RESERVED);
+ changed = true;
+ continue;
+ }
+ if (start < start_aligned) {
+ e820_update_range(start, start_aligned - start, E820_RAM, E820_RESERVED);
+ changed = true;
+ }
+ if (end_aligned < end) {
+ e820_update_range(end_aligned, end - end_aligned, E820_RAM, E820_RESERVED);
+ changed = true;
+ }
+ }
+
+ if (changed) {
+ sanitize_e820_map();
+ printk(KERN_INFO "aligned physical RAM map:\n");
+ e820_print_map("aligned");
+ }
+}
+
void __init finish_e820_parsing(void)
{
if (userdef) {
@@ -922,6 +963,9 @@ void __init finish_e820_parsing(void)
printk(KERN_INFO "user-defined physical RAM map:\n");
e820_print_map("user");
}
+
+ /* In case, We have RAM entres that are not PAGE aligned */
+ e820_align_ram_page();
}

static inline const char *e820_type_to_string(int e820_type)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/